The present invention relates to a new and improved construction of a closure device for a bottle or the like and a method of manufacturing the same.
Generally speaking, the closure device of the present invention is in the form of a closure cap which serves to close a bottle or similar containers or receptacles having a neck provided with a dispensing or pour opening, a neck end surface surrounding the dispensing opening and a mouth bead located below the neck end surface and having at its underside a constricted portion. The closure cap possesses a claw cap which comes to lie above the dispensing opening and covers the same at least at its outer region. The claw cap is provided with a roof or ceiling wall which continues in the form of a number of arms past the mouth bead and has claws which come to lie in the constricted portion. The claw cap carries a pressure ring which, in the closed position of the closure cap upon the bottle, fixedly presses the arms and claws against the mouth bead in such a manner that the closure cap is fixedly connected with the mouth bead of the bottle.
In order to close the most different types of bottles or flasks, extending from ampule bottles to beer bottles and up to salad oil bottles fabricated from plastic materials, there are required positive closure devices of the above-described type.
There are already known to the art such type of closure devices, for instance from U.S. Pat. No. 2,671,572 of William Satz, granted Mar. 9, 1954. Also in German Patent Publication No. 2,210,414 of Albert Obrist & Co. and German Patent Publication No. 2,319,617 of Jean Grussen, there have been disclosed bottle closures provided with ring elements, which can be pivotably attached to a cap and are connected at the cap circumference by means of small tear webs with the cap prior to the initial opening of the bottle. The undamaged webs only indicate that there has not yet occurred any opening of the filled bottle. The ring element, following the tearing of the webs, serves as a grip ring for the decapping of the bottle and for the removal of the cap during each further opening of the bottle. However, none of both of the last-mentioned ring elements contributes to the improved attachment of the cap at the flask or bottle mouth while encountering the internal pressure within the bottle. The bottle closure described in U.S. Pat. No. 3,825,144 of Walter Wiedmer is either sprung off the bottle when encountering even the most relatively slight pressure increase within the bottle, or it is too stiff and therefore is seated much too rigidly in order to be easily opened with the finger of a hand of the user.
In contrast to these ring elements the ring element provided in the aforementioned U.S. Pat. No. 2,671,572 of William Satz plays a decisive role during the sealing closing operation. Yet, such ring element is associated with certain drawbacks. It should not be too elastic in order that it is capable of sealingly pressing the slotted lateral cap wall satisfactorily against the mouth bead. Additionally, at the lifting side there does not prevail any contact between the ring element and the lateral cap wall over a region corresponding to an arc of about 40 degrees. To ensure that there is accomplished a uniform pressing of the lateral cap wall against the remaining circumferential region of about 320 degrees, it is necessary that the ring element be constructed to be relatively rigid, and therefore it acts upon the lateral cap wall more in the manner of exerting a retention action than a pressing together action, i.e. the lower end region of the tongues are passively prevented from spreading apart by the underside of the mouth bead of the bottle when there prevails an increased pressure internally of the bottle, for instance due to a temperature increase or shaking or jarring of the bottle, but however these tongues are not actively pressed against the underside of the mouth bead. If the latter occurs then the pressure exterted by the ring element upon the lateral cap wall must be so strongly dimensioned that there is rendered more difficult lifting-off of the ring element for the purpose of opening the bottle.
Yet, all of the heretofore known closure elements possess relatively decisive drawbacks, whether such be that they only can be used to a limited degree, or that they consist of a number of individual parts which must be properly positioned in order to assemble the closure element.